1. Field of Invention
The present invention relates to a solid oxide fuel cell and, more particularly, to a solid oxide fuel cell that requires a limited amount of external energy.
2. Related Prior Art
Referring to FIG. 3, a conventional solid oxide fuel cell includes a core 20, a first heater 21 connected to the core 20, a reformer 22 connected to the first heater 21, a first heat exchanger 23 connected to the reformer 22, a burner 24 connected to the first heat exchanger 23 and the core 20, a second heater 25 connected to the core 20, a second heat exchanger 26 connected to the second heater 25 and the burner 24, a fuel supply 27 connected to the first heat exchanger 23, a liquid supply 28 connected to the first heat exchanger 23 and an gas supply 29 connected to the second heat exchanger 26. The core 20 includes an anode inlet, an anode outlet, a cathode inlet and a cathode outlet although not shown. The fuel supply 27 includes a fuel reservoir 271 and a flow controller 272. The liquid supply 28 includes a liquid reservoir 281, a pump 282 and a third heat exchanger 283. The gas supply 29 includes an air reservoir 291 and a flow controller 292.
Fuel is provided to the first heat exchanger 23 from the fuel supply 27 while water is provided to the first heat exchanger 23 from the liquid supply 28. The fuel and water are pre-heated in the first heat exchanger 23. Then, the fuel and water are transferred to the reformer 22 in which they are reformed. The reformed fuel is transferred to the first heater 21 in which it is heated. The reformed fuel is transferred to the core 20 through the anode inlet. Fresh air is provided to the second heat exchanger 26 from the gas supply 29. The fresh air is pre-heated in the second heat exchanger 26. Then, the fresh air is transferred to the second heater 25 in which it is heated. The fresh air is finally transferred into the core 20 through the cathode inlet. Incompletely burned fuel is transferred to the burner 24 from the core 20 through the anode outlet. The incompletely burned fuel is burned in the burner 24. Used air is transferred to the first heat exchanger 23 from the core 20 through the cathode outlet. The used air is pre-heated in the burner 24. Then, the used air is transferred to the burner 24 to help the combustion of the incompletely burned fuel. In the core 20, chemical reactions occur, thus generating electricity.
The first heater 21, the second heater 25 and the third heater 283 are heat tapes that require a lot of external energy for heating. Therefore, the efficiency of the conventional solid oxide fuel cell is low.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.